Because 42.1 is no longer supported, that could be a bit of work…
Steps can be skipped, but at your own risk. If you have good, verified backups and depending on the value of your machine vs re-installing new, there are probably a variety of steps you can take a chance skipping… like updating 42.1 before upgrading, skipping 42.2 and maybe even 15.0 versions, but at your risk. The following more or less describes all the steps you should do if you want best chances to succeed…
An outline of what you should do…
You may want to back up your current repo list and configuration, but anything pointing to 42.1 sources are probably worthless anyway. To backup, run the following command
cp -Rv /etc/zypp/repos.d /etc/zypp/repos.d.Old
Update your system before any upgrades… Because the 42.1 oss update repo is no longer online, you’d have to point to an archive repo, eg at the following location
https://ftp5.gwdg.de/pub/opensuse/discontinued/update/leap/42.1/oss/
You may want to similarly point to point to the non-oss update repo although that’s less important.
Disable all repos except for the oss and non-oss, and your newly configured oss update repo (and maybe your non-oss if you configured that also).
If you did a “zypper clean” you may have to also point to regular oss and non-oss archive repos (besides the update repos).
You can use YaST Repository Management to add and disable your repos or use zypper for disabling repos.
Update your system running
zypper up
Reboot.
Now, set up an upgrade from 42.1 to 42.3.
You can change all your 42.1 to 42.3 repos with the following command
sed -i 's/42.1/42.3/g' /etc/zypp/repos.d/*
Display your repos
zypper lr -d
Verify only the oss, non-oss and oss-update and non-oss-update repos are enabled and URLs say “42.3”
If all looks correct, then execute your update fro 42.1 to 42.3, notice the “dup” instead of “up”
zypper dup
Reboot.
Now, for each upgrade from 42.3 to 15.0 or 15.1, repeat the above upgrade steps from 42.1 to 42.3, except change the numbers in your sed command to correspond with your upgrade step.
When you have upgraded to 15.1 and rebooted,
Re-enable your disabled repositories and run a system update (zypper up).
And, you’re done.
In the above, I only described the less usual commands to do things mostly and didn’t describe commonly used zypper commands for add/remove/enable/disable repos, if you want to use zypper instead of YaST for your repository management, ask and I (or someone else) can post those, too.
Good Luck,
TSU
